Improvement in saw-mills



aient )iii r i GEORGE L. MCCAHAN, OF BALTIMORE, MARYLAND.

, Leim-s Patent No. 92,463, dated .my 13, 1869'.

IMPROVEMENT IN SAW-MllLLS.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom fit may concern.- v

vBe it known that I, GEORGE L. MCCAHAN, ofthe 'city and county of Baltimore, and State of Maryland,

have invented a new and improved Feed-Gear for Saw-Mills; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference -being had to the accompanying drawings, making a part of vthis specification, in which- Figure 1 is a vertical section through line :c :i: of fig. 2.

Figu 2 is a plan.

Figure 3 is a detached side view of the movable journal-box and the lever-fulcrum, a portion of the wall having been broken away to show the operation of the box and spring.

lhe object of this invention isvto provide for public use a more simple and perfectly-operating feed-gear for saw-mills than any heretofore employed. To this end,l

The invention consists in a novel construction and combination of grooved frictionfear for feeding the log to the saw, with belt and pulley for gigging the carriage back, the gear `and belt being so adjusted and applied, that when one is thrown into operationby means ot' a lever, the other is released at the same instant and thrown out of operation. This effect is produced in the most simple and convenient manner, by causing the lever to operate a tighteningpulley on one side of the .fulcrum, and an adjustable 'journal-box, supported by a spring for the grooved friction-gear wheel on the other side. When the handle of the lever is depressed, it raises the tightening-pulleyr and slackens the gig Ting-back belt, permitting it to run free, and at the same instant depresses the journal-box, and brings the t-wo grooved gear-wheels in contact for feeding; and when raised it allows the said gear-wneels to be separated again bya spring, permitting them in their turn to run free, while at the' same instant it tightens the gigging-back belt, and changes the movement of the carriage.

The foregoing description alludes particularly to the alternate feeding and gigging'back of the carriage during the actual sawing of a log; and as. it is customary to keep the saw-mill in motion at a reduced Speed during the settingl and turning of the log, and also while supplying a fresh log to be. sawed, the feeding and gigging-hack motions are both rendered inoperative, by so constructing the lever that it will be nearly balanced on its fulcrmn a sufficient excess of weight over a true balance being put in the end towards the operator, to keep the lever in a horizontal position, resting on the adjustable journal-box, supported by the spring, and still insufficient to depress the box until other and additional pressure is applied by the operator.

In the drawings- A is the frame of the machine.

B, the saw.A

C, the saw-mandrel.

D, the shaft that moves the log-carriage towards or from the saw.

E, a large grooved friction-gear wheel,4 attached to shaft D.

F, a small grooved friction-gearwheel, attached to a shaft, G, and working in connection with the wheel H, a tight belt, running from a pulley, I, on the mandrel, to a pulley, J, o n shaft G, for the purpose of operating the latter to feed the log to the saw.

K, a loose belt, running from a pulley, M, on the mandrel, to a pulley, N, on shaft l), for the purpose of gigging the log-carriage back.

O, a support and guide for the vertically-sliding journal-box of shaft G, at the gear-end of said shaft P, the journal-box itself.

Q, a spring under the journal-box, tending to force the latter up, so as to raise the end of the shaft and ungear the wheels E F.

L, a hand-lever, pivoted at l to the support O, so asto press at m upon'the box P, and having a tight.- ening-pnlley, R., at the end opposite to the handle; and

S, a hanger, or journal-box, to support the end of shaft G, opposite to the gear-wheel F, the bearing being mounted on trunnions s s, bearing in astandard 0r socket s', as shown in the drawings, and for the purpose of accommodating the motion of shaft G, as the opposite end of the latter is raised or depressed.

The operation of this improved feed-gear is as follows: 1

The mandrel C being set in operation, the belt H drives shaft G in the same direction, and the frictiongear F E, reversing the motion, transmits it to shaft l), so as to move the carriage towards the saw, the belt K running loosely all the-while, and the pressure applied by the operator to the larger arm of level' l., overcomes the force of spring Q, and keeps the wheels E F in gear. \Vl1en the saw has cut through the log, the operator, raising the handle of lever L, throws pulley' R down on belt K, so as to tighten the latter. At the same instant that the short arm of the lever is tlms depressed to apply the pulleyLR, the pressure of the long arm is removed from journal-box P, and enables spring Q to raise the latter and throwthe wheels E F out of gear. The motion of mandrel C is now applied to shaft I), through the pulleys M N, and belt K, and runs the carriage rapidly back to the p oint ii'om which it started.

Having thus described my invention,

What I claim as new, and desire to secure by Letters Patent, is-

` l. lrhe vertically-1novablejournal-boxl),constructed to operate in connection with lever L. and 'spring Q, substantially as and for the purposes set forth.

L. The combination of the verticaliy-movable jour-l nal-box l, with shaft G, grooved friction-wheels .E F,

lover L, belt-K, and pulleys R M N, whenconstructed to operate as and for the purposes set fort-h.

GEORGE L. McOAHA-N.

Witnesses JAMES H. GRIDLEY, Cans. A.PETT1'1. 

